Conventionally, an example of a vehicle seat slide device as described in Patent Document 1 has been known. Such a vehicle seat device includes a pair of lower rails fixed on a vehicle floor and a pair of upper rails fixed to a seat. The upper rails are supported by the lower rail to be movable relative to the lower rails. Each lower rail has a pair of plate-like stoppers at a center portion in the longitudinal direction. The stoppers are formed by cutting and raising parts of the bottom wall of the lower rail. On the other hand, each upper rail has a pair of plate-like stoppers at either end in the longitudinal direction. The stoppers are formed by cutting and raising parts of the vertical walls of the upper rail. The stoppers at each end of the upper rails can contact and be engaged with the stoppers of the lower rails along the moving direction of the upper rails, so that the range of movement (slide stroke) of the upper rails relative to the lower rails is limited.
In the seat slide device of the above publication, the impact of contact between the stoppers can elastically deform the stoppers so that the engaging position between the stoppers is displaced toward the stopper distal ends (free ends), that is, in a direction disengaging the stoppers from each other. In this case, it is possible that the movement range of the upper rails relative to the lower rails cannot be limited.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-298104